This ignores the lower marginal utility of money as wealth increases (and increased marginal tax burden), and probably greater marginal "utility" of having chil

This ignores the lower marginal utility of money as wealth increases (and increased marginal tax burden), and probably greater marginal "utility" of having children at higher levels of wealth (as you have more ability to spend time with them/don't need to be preoccupied with economic worries. e.g. my wife is a stay-at-home mom and I can work from home, so we get to spend a lot of time with our kids).